Proper treatment and diagnosis of a patient often involves a thorough examination or internal organs and structures. To conduct an examination, a clinician often uses a visualization device to probe ducts, orifices, bodily openings, or other spaces. One such device is an endoscope, typically constructed of a long thin probe that employs optical fibers to transmit images of interior bodily structures. Previously-known endoscopes suffer a number of disadvantages, including initial capital cost, limited upgradeability to take advantage of improving camera technology, limited illumination capability, and the need for sterilization after each use.
Previously-known endoscopes typically have similar design based on the parts used and placement of these parts. A basic design may include no illumination, which is then added to capture images under low-light conditions. Fiber optics often are used to transmit light to the distal end of low profile endoscopes, although the illumination typically comes from a separate and rather large box with the light source. For example, U.S. Pat. No. 5,394,865 to Salerno describes an endoscope that utilizes fiber optic cables to transmit light to the distal end of the device to illuminate the work area. This device is designed to be reused and sanitized in an autoclave. Such sterilization procedures are time consuming and expensive, and inherently present a non-negligible risk of contamination and infection. Accordingly, it is desirable to provide an endoscope that does not require sterilization by autoclave after use.
U.S. Pat. No. 6,117,071 to Ito, et al. describes an endoscope having a CCD located in an imaging unit near its distal end to gather images. In addition to requiring sterilization after each use, the device described in Ito also has a relatively large insertion profile, i.e., cross sectional area, that limits its use to correspondingly large openings. U.S. Patent Application Publication No. US 2007/0162095 to Kimmel et al. describes a modular visualization stylet that overcomes certain of the disadvantages of prior art devices such as described in Ito, but such devices have not achieved commercial success.
A key drawback inherent in previously-known endoscopes, particularly low-cost disposable endoscopes, is the inability to provide bright, uniform illumination at the work area, irrespective whether the illumination is conducted to the distal end of the endoscope by a light fiber or generated nearer to the distal end of the device using light-emitting diode (“LED”) technology. For example, U.S. Pat. No. 8,484,966 to Robertson describes an endoscope having a monolithic distal tip that encases an illumination source consisting of either the distal end of a light fiber or one or more LEDs. In view of the domed shape of the distal tip of the device described in Robertson and the location of the light fiber tips or LEDs, the Robertson device is not expected to provide uniform illumination at of the work area.
Likewise, U.S. Patent Application Publication No. US 2007/0162095 to Glassenberg et al. describes a modular visualization stylet in which an imaging element is disposed within a tubular member with a plurality of LEDs disposed in an annular array around the imaging element. This design also is expected to provide uneven lighting at the work area due to variations in the intensity of the LED lighting.
In view of the drawbacks of previously-known endoscopes, it would be desirable to provide an endoscope having a low cost, disposable illumination and camera module that provides uniform lighting in the field of view of the imaging system.
It further would be desirable to provide an endoscope having a low cost, disposable illumination and camera module that permits easier upgradeability and integration with improvements in camera technology, while preserving the capital investment in reusable portions of the endoscope system.